Grommets are used to establish seals between vehicular transmission case bore holes and oil fill tubes that are advanced into the bore holes. More particularly, a grommet in the form of an o-ring or other annular resilient sealing device is positioned in a bore hole of a transmission case between the case and an associated oil fill tube to prevent leakage of transmission oil between the tube and case. Accordingly, existing transmission bore hole sealing grommets are annular, and consequently are formed with a hole through which the transmission oil fill tube is positioned.
Typically, a transmission oil fill tube is not positioned in the bore hole of a transmission case until after the case has been manufactured and tested. Because such pre-assembly testing ordinarily includes pressurizing or evacuating the transmission case and then measuring the decay of the pressure/vacuum, the temporarily empty bore hole consequently must be plugged.
Also, after testing but before installation of the oil fill tube, the transmission case might be transported. It is desirable to keep contaminants out of the case during transportation, so once again the bore hole must be covered. Moreover, it is desirable to eliminate the entrance of contaminants into the transmission case via the bore hole during installation of the oil fill tube. Unfortunately, existing oil fill tube grommets are useful only for establishing a seal between the oil fill tube and the transmission case after the tube has been installed. Consequently, other means currently are required to seal the bore hole prior to oil fill tube installation for the reasons stated above. As recognized by the present invention, however, a transmission oil fill tube grommet can be provided which not only establishes a seal between an oil fill tube and a transmission case, but which can plug an oil fill tube bore hole during transmission case testing, transmission case transportation, and oil fill tube installation.
Accordingly, it is an object of the present invention to provide a transmission oil fill tube grommet which can establish a seal between the tube and a transmission case in which the tube is received. Another object of the present invention is to provide a transmission oil fill tube grommet which covers a transmission case bore hole prior to installation of an oil fill tube in the bore hole. Still another object of the present invention is to provide a transmission oil fill tube grommet which is easy to use and cost-effective to manufacture.